C / C++ / MFC

17-Apr-07 10:22

i'm quite new to mfc/c++ and i'm trying to create a really simple dialog box which controls the master volume of a simple form view application.. i've created the dialog and the variables to control the master volume in the form class (i've tested by creating a control in the form view and this works fine) but when i try to access and alter the form parameter from the dialog using a pointer and GetParent() during OnTimer(), it just does nothing... am i missing something?

thanks in advance

led mike17-Apr-07 11:36

led mike

17-Apr-07 11:36

bimgot wrote:
am i missing something?

Just a WAG: UpdateData()

led mike

bimgot17-Apr-07 12:07

17-Apr-07 12:07

have tried UpdateData()

does the dialog class require any settings in order to access the parent variables? i've even tried just very simple variable tests in OnTimer in the dialog class and it seems to have no effect on them.. is OnTimer even the right function to be using? i use it in the main form for a simelar process so i figured it would be but perhaps its different for dialogs?

David Crow17-Apr-07 16:43

17-Apr-07 16:43

bimgot wrote:
...it just does nothing...

Which means "nothing" without any supporting data. Does GetParent() return the correct parent address? How about a snippet of code that shows what does not work?

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

bimgot18-Apr-07 0:36

18-Apr-07 0:36

OnTimer in the dialog class:
void CDlg::OnTimer(UINT_PTR nIDEvent)
{
CDialog::OnTimer(nIDEvent);
dlg_level = dlg_sldr.GetPos();

CformView* form = (CformView*) GetParent();
form->form_level = dlg_level;
form->UpdateData(TRUE);

UpdateData(TRUE);
}

then from form view class:

void CformView::OnViewDlg()
{
CDlg dialog;
dialog.dlg_level = form_sldr.GetPos();
dialog.DoModal();
}

hope this makes sense

JudyL_MD18-Apr-07 2:39

JudyL_MD

18-Apr-07 2:39

UpdateData (TRUE) puts the values currently in the controls into the variables. You need to call UpdateData (FALSE) to move the variable values into the screen controls. Note that I have added a line. This is so that if you have other controls on the screen, you won't lose the values the user might have changed on the screen when you call UpdateData (FALSE).

void CDlg::OnTimer(UINT_PTR nIDEvent)
{
CDialog::OnTimer(nIDEvent);
dlg_level = dlg_sldr.GetPos();

CformView* form = (CformView*) GetParent();
UpdateData (TRUE);
form->form_level = dlg_level;
form->UpdateData(FALSE);

UpdateData(TRUE);
}

Judy

David Crow18-Apr-07 2:46

18-Apr-07 2:46

JudyL_FL wrote:
UpdateData (TRUE) puts the values currently in the controls into the variables. You need to call UpdateData (FALSE) to move the variable values into the screen controls.

All the more reason why UpdateData() should rarely, if ever, be used.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

bimgot18-Apr-07 3:25

18-Apr-07 3:25

thanks very much, i understand UpdateData a bit more now,
i think i must have initialised something incorrectly, this still doesnt seem to update the values in the form.. the pointer to the main form is working correctly, if i call something like form->CloseWindow() during OnTimer it works..

i'm using OnTimer() in the main form to actually call the function which sets the volume:

void CformView::OnTimer(UINT_PTR nIDEvent)
{
CFormView::OnTimer(nIDEvent);
SetVolume(form_level);
UpdateData(FALSE);
}

would this still get called during the life of the dialog or do i need to set the volume somewhere else?

also is it possible some of the properties of the dialog could be effecting things?? really racking my brain here..

thanks

David Crow18-Apr-07 2:51

18-Apr-07 2:51

How does this answer the question, "Does GetParent() return the correct parent address?"

void CDlg::OnTimer(UINT_PTR nIDEvent)
{
    CDialog::OnTimer(nIDEvent);
    dlg_level = dlg_sldr.GetPos();
 
    CformView* form = (CformView*) GetParent();
    // what is the value of 'form' here?
    form->form_level = dlg_level;
    form->UpdateData(TRUE);
 
    UpdateData(TRUE);
}
 
void CformView::OnViewDlg()
{ 
    CDlg dialog;
    // what is the value of the 'this' pointer here?
    dialog.dlg_level = form_sldr.GetPos();
    dialog.DoModal();
}

Since CDlg is a modal dialog, I question whether this will even work, since messages sent to its parent will be blocked until DoModal() returns.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

bimgot18-Apr-07 3:48

18-Apr-07 3:48

void CDlg::OnTimer(UINT_PTR nIDEvent)
{
CDialog::OnTimer(nIDEvent);
dlg_level = dlg_sldr.GetPos();

CformView* form = (CformView*) GetParent();
// form points to the main form class correctly
form->form_level = dlg_level;
form->UpdateData(TRUE);

UpdateData(TRUE);
}

void CformView::OnViewDlg()
{
CDlg dialog;
// this points to the main form class as this is a member function
dialog.dlg_level = form_sldr.GetPos();
dialog.DoModal();
}

i did consider a modal dialog as bieng inappropriate for this but was unsure as i dont actually need to control the main window whilst the dialog is open, i just want to update some variables..

David Crow18-Apr-07 3:59

18-Apr-07 3:59

bimgot wrote:
...i dont actually need to control the main window whilst the dialog is open, i just want to update some variables..

So why call UpdateData() then?

void CformView::OnViewDlg()
{ 
    CDlg dialog;
    dialog.dlg_level = form_sldr.GetPos();
    dialog.DoModal();
    // is form_level correct at this point?
}

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

bimgot18-Apr-07 5:21

18-Apr-07 5:21

i dont believe it is no.. if i call

void CformView::OnViewDlg()
{
CDlg dialog;
dialog.dlg_level = form_sldr.GetPos();
dialog.DoModal();
form_sldr.SetPos(dialog.dlg_level);
}

this updates the variable when the dialog is closed, but i want to update the variable as the dialog is running..
trying the same but with:

form_sldr.SetPos(form_level); after DoModal();

doesnt update the control in the same way..

David Crow18-Apr-07 5:25

18-Apr-07 5:25

bimgot wrote:
i want to update the variable as the dialog is running

Which contradicts your earlier statement of, "...i dont actually need to control the main window whilst the dialog is open." Confused | :confused:

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

bimgot18-Apr-07 5:30

VC++ Class Diagram resolution.

18-Apr-07 5:30

sorry i was unclear here,
i need to control the window in that i want to be able to update its variables, but i dont need to physically control or move the window..

oleg6317-Apr-07 10:08

oleg63

17-Apr-07 10:08

Hi,

Would be good to get my unmanaged C++ Class Diagram, but...
Since the Class Diagram feature is not implemented for VC++ 2005 (only for C# and Visual Basic .NET ),
is there some existing 3-rd party plugins for C++(unmanaged) VS2005?

Thanks,
Oleg.

Help

tanchinchee17-Apr-07 7:01

17-Apr-07 7:01

Hi,
i am trying to develop a table which contain the following:

No Name I/C number Experiment Group
Week1 Week2 Week3
1 Tan Chin Chee 1234456666 Exp 1 Exp 2 Exp 3 A
2 AKKKKKKKKKKKK 3847384737 A
3
4
5

6 Adrian 565565656 Exp 2 Exp 3 Exp 1 B
7

Well the problem here is a have to read the name from a name list of 66 person. And i cannot cout their name. Since in the name list all the name will be written in such way (Tan Chin Chee). After the space it, the next char will be store as some other thing else(not name). And how do i make a space after the group A. Where you can see after number 5, there is a space before going to number 6.

Thanks.

p/s : I am using c++

Arman S.17-Apr-07 7:19

Arman S.

17-Apr-07 7:19

between 5 and 6 there is an empty line;
cout << "\n";
Spaces?.. What's the problem;
cout << " ";
To tabulate;
cout << "\t";

--
======
Arman

tanchinchee17-Apr-07 7:24

17-Apr-07 7:24

<br />
#include<iostream.h><br />
#include<fstream.h><br />
#include<stdio.h><br />
#include<cstring.h><br />
<br />
void main()<br />
{<br />
int i=0;<br />
int num[66];<br />
string d_ic;<br />
<br />
ifstream infile("C:\\section17.txt");<br />
<br />
while(i<66)<br />
{<br />
infile>>num[i]>>d_ic;<br />
{<br />
if(num[i]<=13)<br />
cout<<num[i]<<"\t"<<d_ic<<"\t"<<"Group A"<<endl;<br />
<br />
cout<<endl;<br />
<br />
else<br />
cout<<num[i]<<"\t"<<d_ic<<"\t"<<"Group B"<<endl;<br />
}<br />
i++;<br />
}<br />
cout<<endl;<br />
cout<<"Hello"<<endl;<br />
<br />
<br />
getchar();<br />
<br />
}<br />

i have a name list of the following
1 123123124124
2 123123123123
3 343242342342
4 123354352525
5 234523525255
6 234523413412
7 123421341234
8 234123423412
9 343434355266
10 123421342423
11 123421561666

And the source code i have written cannot produce the required form of table.

sthotakura17-Apr-07 7:45

sthotakura

17-Apr-07 7:45

Did you try gets()?

Cheers,
Suresh

tanchinchee17-Apr-07 7:51

17-Apr-07 7:51

i have did that. Can i do the same if the name is not key in by the user. Because i need to read the name directly from a name list given.

David Crow17-Apr-07 7:50

17-Apr-07 7:50

The code snippet you've shown here, and the problem/request in your initial post, do not even come close to matching. Explain clearly what you are after.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

tanchinchee17-Apr-07 7:56

17-Apr-07 7:56

Well, in the code i have sent i am trying to show the following :

1 12312312312 Group A
2 12155132415 Group A
3
4
5
6
7

8 4325141235 Group B
9
10

In my initial post i am requesting for help to show the names. Since i can't do that so i am trying to at least show the identification number(I/C) and the group. Also with the spacing after number 7(in my code, after number 13. I have 66 i/c in my name list) The problem i have encountered is that after the spacing the i/c for group B cant't be shown. Why is that?

Maximilien17-Apr-07 7:23

Maximilien

17-Apr-07 7:23

separate each field with a comma :

1, Tan Chin Chee, 1234456666, Exp 1, Exp 2, Exp 3, A

or put " around strings

1 "Tan Chin Chee" 1234456666 "Exp 1" "Exp 2" "Exp 3" "A"

or store your file as an xml file.

Maximilien Lincourt
Your Head A Splode - Strong Bad

tanchinchee17-Apr-07 7:27